This section provides background information related to the present disclosure which is not necessarily prior art.
Brain cancer is the leading cause of cancer-related death in patients younger than age 35 and accounts for roughly 10% of all cancers diagnosed in North America. Treatment of brain tumours is complicated by the fact that there are more than 120 different types, which range from low grade astrocytomas to high grade glioblastomas (GBM). Malignant gliomas, such as GBM, are by far the most common brain cancer found in adults and one of the most difficult to treat. Even with aggressive single and multimodal treatment options such as surgery, chemotherapy, radiation and small molecule inhibitors, the survival has remained unchanged over the past three decades with a median survival of less than one year after diagnosis. Reasons for the failure of conventional treatments is multifactorial including the highly infiltrative/invasive nature of GBM, limitation of drug delivery through the blood brain barrier and neural parenchyma, and genetic heterogeneity resulting in intrinsic resistance to available treatments and the rise of aggressive resistant clones. Therefore, there is a dire requirement for new treatment options, which has led to the renaissance of oncolytic viral therapy for GBM.
Currently, the efficacy and safety of several oncolytic viruses with various tumour targeting strategies are being evaluated in the lab and clinic against GBM. The rhabdovirus vesicular stomatitis virus (VSV) constitutes one of these efficacious viruses being tested preclinically. However, a desired route of viral administration for GBM is intracerebral delivery, which is not currently possible with VSV due to its neurotoxicity.